Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; Shandong Key Laboratory of Biochemical Analysis; Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; Shandong Key Laboratory of Biochemical Analysis; Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Biosens Bioelectron. 2019 Feb 15;127:64-71. doi: 10.1016/j.bios.2018.11.043. Epub 2018 Dec 7.
Sensitive but with simple, inexpensive detection of disease-related biomarkers in real biological samples is of quite necessity for early diagnosis and disease surveillance. We herein first introduced high-activity FeO nanozyme as signal amplifier to develop an ultrasensitive photoelectrochemical (PEC) immunoassay, which meanwhile has the distinct merits of both simplicity and low cost compared with previously reported enzyme-labeling PEC immunoassays. In the proposal, to illustrate and describe the PEC platform, prostate-specific antigen (PSA, Ag) was used as a target model. Specifically, ZnO nanorods (ZnO-NRs) grown vertically on a bare indium-tin oxide (ITO) electrode was deposited with ZnInS nanocrystals, producing ZnInS/ZnO-NRs/ITO photoelectrode as the PEC matrix to modify capture PSA antibody (Ab). Histidine-modified FeO (his-FeO) nanozyme as signal amplifier was linked with signal PSA antibody (Ab) to form his-FeO@Ab conjugate, and was anchored through specific sandwich immunoreaction. The labeling his-FeO nanozyme acted as a peroxidase to induce the generation of the insoluble and insulating precipitation, resulting in an evident decrease in the photocurrent signal. On account of combined effects of high catalytic efficiency of the his-FeO nanozyme and excellent PEC properties of the ZnInS/ZnO-NRs/ITO photoelectrode, ultralow detection limit of 18 fg/mL for target Ag detection was achieved. Besides, as high-activity his-FeO nanozyme has substituted natural enzyme as signal amplifier, simplicity and low cost of the PEC immunoassay was realized.
在真实生物样本中，对与疾病相关的生物标志物进行敏感而简单、廉价的检测，对于早期诊断和疾病监测是非常必要的。本文首次介绍了高活性 FeO 纳米酶作为信号放大器，开发了一种超灵敏的光电化学（PEC）免疫分析，与之前报道的酶标记 PEC 免疫分析相比，具有简单和低成本的明显优点。在该方案中，以前列腺特异性抗原（PSA，Ag）为目标模型，来举例说明和描述 PEC 平台。具体来说，将垂直生长在裸氧化铟锡（ITO）电极上的氧化锌纳米棒（ZnO-NRs）沉积上 ZnInS 纳米晶体，产生 ZnInS/ZnO-NRs/ITO 光电电极作为 PEC 基质来修饰捕获 PSA 抗体（Ab）。组氨酸修饰的 FeO（his-FeO）纳米酶作为信号放大器与信号 PSA 抗体（Ab）相连形成 his-FeO@Ab 缀合物，并通过特异性三明治免疫反应固定。标记的 his-FeO 纳米酶作为过氧化物酶起作用，诱导不溶性和绝缘沉淀的生成，导致光电流信号明显下降。由于 his-FeO 纳米酶的高催化效率和 ZnInS/ZnO-NRs/ITO 光电电极的优异 PEC 性能的综合影响，实现了对目标 Ag 检测的超低检测限 18 fg/mL。此外，由于高活性 his-FeO 纳米酶替代了天然酶作为信号放大器，实现了 PEC 免疫分析的简单和低成本。
